The present invention relates to a method and apparatus for facilitating recognition of characters, particularly handwritten characters, in systems such as optical character recognition machines.
Recognition of handwritten data in prior art optical character recognition machines has presented substantial problems. Unlike standardized machine print which presents characters in a fixed format for relatively straight forward recognition by processing circuitry, handwritten characters can vary substantially from the recommended format in accordance with the care taken by the individual responsible for writing the data. Consequently, both the height and width of handwritten characters can vary significantly from a pre-specified format, in which case recognition by standard prior art optical character recognition machines is impossible.
Although not expressly described in terms of optical character recognition, U.S. Pat. No. 2,964,734 to George P. West describes an electronic handwritten character recognition approach which allows considerable character configuration variation without introducing recognition error. The characters to be recognized by the system of the West patent are transcribed with a substance designed to vary an electrical characteristic such as current conductance, flux permeability or capacitive charge. The sensing device includes a group of sensing elements or electrodes which are arranged to detect predetermined conditions or features in a character configuration. In effect, these electrodes look for line crossings at different locations within the character and decode such line crossings to provide an indication of the character.
The technique described in the aforementioned West patent is for more suitable for use in optical type character recognition machines than the techniques presently used in most such machines. Consequently, the system of which the present invention is a part utilizes a variant of the West approach for handwritten character recognition. Nevertheless, even with this approach there are certain recognition ambiguities which prevail and reduce the recognition accuracy of the system. Some of these ambiguities include recognizing differences between handwritten: 0's and 8's; 0's and 9's; 8's and 9's; 7's and 9's; 7's and 1's; 9's and 1's; 3's and 5's; 3's and 2's; 3's and 8's; and 2's and 7's.
It is therefore an object of the present invention to provide a method and apparatus which eliminates the aforementioned handwritten character recognition ambiguities and thereby improve the recognition accuracy of character recognition machines of any type and particularly of the optical type.
It is a more specific object of the present invention to provide a method and apparatus which is general in application but has particular utility when used in conjunction with the system described in the aforementioned U.S. Patents to provide unusually high reliability in the recognition of handwritten characters.